Streamcurrent apparatus for mixing materials



Jan. l, 1946. A AUER I y 2,391,858

STREAMCURRENT APPARATUS FOR MIXING MATERIALS Filed July 3l, 1943 6Sheets-Sheet 1 Jan. 1, 1946. G. A. AUER STREAMCURRENT' APEAARATUS FORMIXING MATERIALS Filed July 5l, 1945 6 Sheets-Sheet 2 Jan. l, 1946. Q AAUER 2,391,858

STREAMCURRENT APPARATUS FOR MIXING MATERIALS Jan. 1, '1946.- V G A,AUER2,391,858

STREAMCURRENT APPARATUS FOR MIXING MATERIALS Filed July 3l, 1945 6Sheets-Sheet 4 INVENTOIL George vvquef- BY i Z. A E gt Z Filed July 3l,1945 6 Sheets-Shea?. 5

`Fam. 1, 1946. G. A. AUER STREAMCURRENT APPARATUS FOR MIXING MATERIALSFiled July 3l, 1943 6 Sheets-Sheet 6 Patented Jan. I, 1946 UNITED STATESPATENT voPEIcE STREAMCURRENT APPARATUS Foa MIXING MATERIALS George A.Auer, Chicago, Ill.

Application July 31, 1943, ASeralNo. 496,920

8 Claims.

This invention relates to streamcurrent process'- ing and isparticularly concerned with a streamcurlrent method and apparatus formixing materia s.

The term--streamcurrent-as dened'and explained in U. S. Patent No.2,386,419, is intended to refer to the contro-1 of a body of a iluid inmotion, in such a manner that the flow thereof is hydraulically stableand rationally predictable, thereby producing conditions wherein fluidand solid particles contained in the medium or passing through or movedby the medium will exhibit a predictable behavior.

The term-mixing-, as used herein, unless otherwise qualified, isintended to mean mixing as generally understood, also homogenizing,emulsil fying, agitating, processing, and like operations, including themixing of normally miscible and normally immiscible liquids, the mixingof substances of diiierent specic gravities, and the dispersion ofcomminuted solids in liquids.

Prior mixers, including devices employing single or multiple propellers,paddles, spiral blades, also the So-called colloid mills wherein thematerial is subjected to shearing and centrifugal forces betweencoacting stator and rotor elements, operate with an obscure element ofuncertainty which is apparently recognized in the art. For example,Chemical Engineers Handbook (1634); p. 1267, records the followingobservation: iAt the present time the subject of mixing probably has theleast scientific foundation of all the unit processes of chemicalengineering. There is no formula or equation which can be used tocalculate the Vdegree or speed of mixing under a given set ofconditions. The reason is 'that the conditions are vso varied that todate they have escaped a mathematical analysis. It is to be hoped thatin time order may be obtained from the chaos now existing. An.- otherauthority, who also discusses some of the above intimated mixingdevices, may be quoted to indicate that the handicaps continue to existup to the present day. H. Bennett, in a book published May 1943,(Practical Emulsions; VChemical 4Publishing Co., Inc), Says: Thehydrodynamics of emulsillcation, i. e., the mechanical forces used toproduce emulsions, is exceedingly complex and is not thoroughlyunderstood. Since these forces are applied most 1in-uniformly it can bereadily seen that such variables will give variable results. It isexceedingly important, in attempting to duplicate known emulsions, thatall forces be duplicated as closely as possible.

The literature does not give explanations that would furnish conclusivereasons for the uncertain performanceofj prior mixers or Wouldoierpractically useful suggestions for remedial steps. 'The situation issummed up, for example, by Hixson and Wilkens (Performance of Agitators.in Liquid-Solid ChemicalSystems; Indus. and Engin. Chem.; Indus. Ed.25; p. 1196-1263; November,

1933) who state that the purposes lfor which mixing operations are usedare exceedingly numerous, but that the laterature contains little offundamental importance on the subject.

The invention contemplates improvements designed to contribute towardovercoming the draw-` backs and handicaps of prior mixers. `It proposesstructures which operate with a greater degree of certainty andlaccuracy, rendering more accurate `and more uniform mixtures in lesstime and at less expenditure of energy than prior devices. Thestructures made in accordance with the invention also kcontribute towardmore accurate duplication of desired operating conditions. Some of thesalient objects and features of the invention are briefly stated below.

The invention provides a mixer comprisingv an improved mechanical mixingdevice of thecolloid mill type for subjecting succesive material vincrements to a controlled processing action, and a new hydraulic mixingdevice for receiving the processed or partially processed materialincrements and for subjecting a mass formed of such increments to adenitely controlled hydraulic interrnixing and nal processing operation.

Another feature resides in the provision of means for imparting to thematerial stream a directional flow, termed stream-current flow, wherebythe iced ,of the material into, through and Ifrom the mixer is keptunder definite control during all phases of the mixing operation.

Still another feature is concerned with the provision of means fordividing the directional ow of material through and within the mixingdevice for rthe purpose of effecting a controlled intermixing ofsuccessively processed material portions.

AA -further object utilizes vthe feature noted in the precedingparagraph, for the purpose of subjecting partially processed material toa re-processing treatment by re-grouping its component parts so as toaccelerate the mixing treatment and the intermixing of the finalproduct.

Additional objects and features relate to structural and functionalimprovements in the mechanoal as well as in the hydraulic aspects ofthenew mixer. Y

The invention will be better understood from the detailed descriptionwhich is rendered abelow Fig. 7 represents a view, partially in section,of y a structural embodiment of a mixer such as diagrammatically shownin Figs. 2 and 3;

Fig. 8 illustrates a mechanical mixer unit, partially in section, asused in the structure shown in Fig. '1;

Figs. 9 and 10 are sectional diagrammatic views taken along lines 9-9and |0-I 0 in Fig. 8; and

Figs. 11, 12 and 13 illustrate details in connection with a modicatlonof a mixer element such as employed in the mixer unit shown in Fig. 8.

Like parts are numbered alike throughout the drawings. Known elementsand details will be described only to the extent required for anunderstanding of the invention.

The present practice is apparent from Fig. l. The raw materials are fedin a stream I 2 to a mechanical mixer I I, e. g., of the colloid milltype and are discharged therefrom in a stream I3. Rev-circulation may beprovided for by directing the discharge for re-treatment through themechanical mixer in a stream indicated in dotted lines I4. Such practiceresults in the previously explained detriments. The diagram is includedherein so as to afford comparison with the operiationsresulting from thenew structures.

An embodiment of the invention is described below with reference toFigs. 2 and 3.

The new unit shown in Fig. 2 comprises a mechanical mixer 20, which maybe of a suitable known colloid mill type, and a hydraulic control devicecomprising a tank 2| which receives the material processed in themechanical mixer. An improved type of mechanical mixer that may be usedin place of the device 2|] will presently be described. The tank 2| isequipped at its bottom with a circular insert or baille 22 forming anannular suction inlet 23 which communicates with the suction chamber 36.The latter is connected with a valved outlet pipe 35. Centrally withinthe tank 2| is disposed a cylindrical insert 24 secured to the insidewalls of the tank 2| by suitable brackets. The lid or cover of themachine is provided With a central tubular member 21 in which may bemounted the bearings for the shaft 26 projecting downwardly and carryinga propeller indicated at 25, The latter is positioned within thecylindrical insert 24. Depending from the lid or cover is a circularinsert or baille 28 forming with the central mounting 21 an annularsuction inlet 29 which communicateswith the suction chamber I6. Anoutlet pipe 34 communicates with this suction chamber. Anotherperipherally disposed insert 3U rforms with the inner wall of the tank2| an annular suction inlet 3| communicating with the suction chamber 32which is provided with an outlet 33. On top of the lid or cover may bedisposed a pressure gauge 4| and a vent valve 42. This valve iscontrolled by a float 43 and is closed by the float when a desiredliquid levelis reached within the tank 2|. Gas pressure then developingon top of the liquid in the tank may be drawn o by way of the pipe 44,valve 45, to the gas outlet, as indicated in Fig. 2.

The unit furnishes several operating possibilities including, first,batch operation involving the preparation of a rough mix within thehydraulic mixer device 2| and subsequent processing of the rough mixthrough the mechanical mixer; second, batch operation by feeding to theunit a rough mix previously preparedA in a separate mixer; and third,continuous operation involving continuous supply of a rough mix andcontinuous Withdrawal of the finished product from selected levels ofthe hydraulic control device.

It will be assumed that it is desired to use the machine as aself-contained unit Which receives materials to be mixed and prepares,iirst, a rough mix which is then processed in the mechanical mixer. Thelid or cover of the machine, Fig. 2, is provided with a manhole orhand-hole (not shown). One phase, for example, the liquid phase, of theproduct is introduced into the machine by way of valve 46, pump 40,valve 41, mechanical mixer 20. The mixer unit may be provided withtemperature control means so as to heat or to cool the liquid as may bedesired. The other ingredients, for example, solids to be dispersed inthe liquid, may be introduced through the above-mentioned manhole. 'I'hepropeller 25 is rotated at a desired speed by a suitable drive so as toset up agitation Within the tank 2| sufiicient to produce a roughmixture of the materials. The principal circulating currents areindicated in Fig. 2 by flow lines. Upon completion of the rough mix,which for most cases may be very incomplete and accomplished veryquickly, the processing may be started.

For this purpose, the rotary speed of the propeller 25 is adjusted to apoint where it has no mixing function proper, but only a iiow controlfunction. The uid material has flooded the suction chambers I6, 32 and36. Rough mix may now be selectively withdrawn from any one or inadjusted amounts in common from all of these suction chambers by way ofthe valves 50, 5|, 52, pump 40, and may be introduced for processinginto the mechanical mixer 20 by way of valve 41. The processed orpartially processed material leaves the mechanical mixer in upwarddirection in a central stream indicated in Fig. 3. The hydraulicdisplacement of the material is upwardly, laterally outwardly,downwardly and laterally inwardly again for intermixture with the streamrising from the mechanical mixer. This controlled flow of the materialeffects a re-grouping of its component parts and thereby accelerates themixing operation. A further regrouping is effected by the Withdrawal ofmaterial from one or from all of the selected levels, namely, from thesuction chambers I6, 32 and 36. The iinal product may be discharged foruse or for storage from the lowermost suction chamber 36 by way of pipe35, valve 52, pump 40, valves 53 and 54. The discharge may also proceedfrom the bottom ofthe mechanical mixer by way of pipe 60, Valve 6| pump40 and valves 53 and 54.

The pump may be used for circulating the fluid mass as described, or itmay be used only for starting the circulation, in the nature of a primerfor the mechanical mixer, and the latter will take care of thecirculating by way of the by-pass shown in dotted lines. The use of thepump may be dispensed with in the case of certain materials.

It is assumed next that a previously prepared rough mix is fed to themachine .for homogenizing. The feed may proceed by Way of valve 46, pump4D, valve 41, through the mechanical mixer 26. As in the former case,the mechanical mixer may be used as a means of pumping the materialsinto the machine by way of the by-pass.` Gas is displaced within thetank 2l as the liquid level therein rises and is discharged through thevent valve 42. When a desired top level is reached the iloat 43 closesthe vent valve 42 and any further gasl discharge in connection withprocesses that evolve gases or vapors will then proceed by Way of pipe44 and valve 45. The propeller 25 is operated at such speed as toproduce a flow control operation directing the liquid mass within thetank '2l in accordance with the flow lines shown in Fig. 2. It should benoted at this point that processed material discharged from themechanical mixer 20k is not haphazardly added to previously dischargedmaterial, but that the discharged mass is subjected to a controlledstreamcurrent iiow which permits orientation of the processed orpartially processed mass and intermixing thereof in accordance withcontrolled and predictable conditions.

Depending on the material, the final product may be obtained in a singlepass through the mill. In this case, when the tank 2l is iilled, theprocessing of the batch is completed, and discharge may proceed aspreviously outlined, either from the lowermost suction chamber 36 orfrom the bottom of the mechanical mixer by Way of valve 6| The dischargemay be forced by using the pump 40, or may be by gravity by way ofvalves v is again subjected to the controlled streamcurrent No irraow inthe hydraulic control device. tional forces come into play, andintermixing is therefore under controlled conditions. The operation isaccelerated due to the continuous regrouping of the component parts ofthe material by virtue of the controlled flow within the tank 2l andalso by virtue of withdrawal of controlled amounts of partiallyprocessed liquid from one or more of the various liquid levels. Itshould be observed that the inlets 29, 3l and 23 communicating with thevarious control chambers I6, 32 and 36 are larranged in such a mannerthat suction forces applied to these inlets will assist the directionalsteamcurrent displacement of the material within the tank 2l. Thesloping walls 'of the inserts 28 and 3B form a symmetrical rtankstructure at the top, and the sloping walls of the insert 22 form withthe outlet of the mixer 28 a similar structure at the bottom. The spacedefined by these elements therefore provides for a symmetric, that is tosay, for a stable hydraulic displacement of the fluid within the tank.The sloping portion of the insert 28 may be disposed in horizontalalignment with the sloping wall of insert 30.

Continuous feed and continuous discharge of proportionate processedamounts of material may also be accomplished with this machine.v Thefeed of materials in the form, .for example, of a rough mix, may beagain by way of valve 46, pump 40 and valve 41, or by the action of themixer unit over the valved by-pass, as previously described. Dependingon the materials to be mixed, it may be found that as soon as a certainlevel within the tank 2l is reached, discharge from one or the other ofthe suction chambers may proceed. For example, material may becontinuously discharged from the chamber i6 by Way of pipe 34, valves 62and 54, the amount of material discharged from this chamber beingreplaced With the raw feed supplied to the machine. Material may also bedischarged in this manner from the peripheral top suction chamber 32 byway Aof pipe 33 and valves 63 and 54. Finally, material may bedischarged from the suction chamber 36 by way of pipe 35, valves 52, 64,65 and 54. The operation accomplishes .not a haphazard and irrationaldischarge from the mechanical mixer 2l), but a final processing withinthe tank 2l and controlled discharge of adjusted amounts of .selectedprocessed material from selected levels of the liquid body in the tank.The discharged material is composed of portions which are subjected toprocessing treatment for variable times.

The embodiment shown in Figs. 4-6, inclusive,

' comprises again a mechanical mixer unit which may be of any suitabletype or may be made in accordance with the structure to be presentlydescribed. This mechanical mixer unit is mounted on top of the hydrauliccontrol device comprising the tank 14. Disposed within this tank is aperforated partition or insert 15. At the bottom of the device is avalve 11 (see also Fig. 6*) which is operable by suitable means, e. g.,a knob or hand-wheel 18. The valve permits adjustment of the ow ofmaterial discharged from the 'mechanical mixer downwardly through thepipe 1B. Around the perforated partition 15 is a space 19. Within thetank 14 on top thereof is a circular partition 82 forming with the pipe16 a suction chamber 83.' A peripherally disposed insert or partitionBil forms with the tank wall and with the perforated insert 15 a suctionchamber 8l.

' Balile or partition means 84 at the bottom of the tank form a. suctionchamber 85. Control means, such es the pressure gauge, as well as thefloatcontrolled vent valve mentioned in connection with the previousembodiment, are omitted in Fig. 4. They may be provided if desired. Theoperation is as follows:

A rough mix may, for example, be supplied to the machine by way of valve90, pump 9|, valve S5. As in the former case, the pump may be used `forobtaining only the initial feed and priming of the mechanical mixer, orits use may be entirely dispensed with and the feed carried on by meansof the pumping action of the mechanical mixer over the by-pass. Thestream is processed -in the mechanical mixer and discharged downwardlythrough the pipe 16, to the annular opening controlled by the valve 11which is suitably adiusted. The material leaving the mechanical mixerthrough the pipe 16 takes an upward. laterally outward, downward andlaterally inward course as .in the previous case. In .the presentinstance, the streamcurrent displacement of the material within thehydraulic control device is regulated by the perforations in thepartition 15 which increase innumber and there- -fore in outflowcapacity upwardly from the bottom. The material takes an upward course,as indicated by the flow lines and is discharged into the tank 19through the perforations in the partition of the tank 15. The flow ofthe liquid mass 'is diagrammatically indicated in Fig. 5. Again.

asin the former case, various modes of operation are possible.

Material may be processed through the mechanical mixer so as to fill thehydraulic control tank and may then be discharged in a batch. In thiscase the successive discharge of the material from the mechanical mixerthrough and from the pipe 15 sets up the currents generally indicated inFigs. 4 and 5 by flow lines, permitting a reorientation of the materialand intermixing or final processing of the component parts thereofsubstantially without creating irrational hydraulic forces. Thisre-orientation or re-grouping of the component parts of the processedmaterials accelerates the final intermixing. The discharge may proceedeither by gravity by way of valve or may be forced by way of pipe 92,valves 93, 94, pump 9| and valve |0|.

Re-processing of the material may be carried out by withdrawingcontrolled amounts of material from selected levels (suction chambers83, 8|, 85) and returning such material by way of valve 94, pump 9|,valve 95 (or by way of the bypass around the pump) to and through themechanical mixer for retreatment.

A continuous process may likewise be carried out with this embodiment bycontinually discharging material from one or several of the suctionchambers 8|, 83, 85 by way of valves |05, |06 and |00, the amountsdischarged being continually supplied by raw mix.

Simultaneous discharge as well as partial recirculation may also bepracticed with this unit. For example, discharge may be carried on fromone or the other of the upper suction chambers 83 and 8|, whilere-circulation of part of the mixture is carried on through pipe 92,valves 93, 94, the re-circulated amount being added to the raw mix fedto the machine by way of valve 90.

The embodiment shown in Figs. 4 and 5,.and

also the previously described embodiment may also be used for the mixingof materials mainly in the hydraulic control device 2| (Fig. 2) or 14(Fig. 4). The mixing action will be accomplished in both cases incontrolled manner, in the first case by the hydraulic currents resultingfrom the upward flow of the material introduced from below, reinforcedand controlled, if desired, by the action of the propeller, and in thesecond case solely by hydraulic currents which always affect the entiretank contents, subjecting the entire mass of material to uniform mixingconditions. The mechanical mixer may in such case be either disconnectedor may serve merely as a feeder for the material stream. Fig. '7 shows astructural embodiment of the machine made in accordance with theprinciples discussed in connection with Figs. 2 and 3. The machinecomprises a mechanical mixer indicated by numeral ||0. Details of thismixer will be explained later on. The mechanical mixer is built as aunit and is attached by means of the flange to the bottom'of the tank||2 of the hydraulic control device. The tank ||2 is reinforced by meansof vertically extending ribs ||3. The machine is provided with legs orstandards I I4 and is mounted on a base I5. Also mounted on this base isthe motor ||6 with its speed control device The motor operates the shaft||8 of the mechanical mixer unit ||0 through suitable gears H9, |20which may be bevel gears or spiral gears as desired or necessary. Thegears are secured in a mounting |2| attached to the base at |22.

The mechanical mixer unit l0 is of the turbine mixer type, as will b eexplained later on more in detail, and is provided with a number ofstators and coacting rotors, the latter being removably mounted insplined connection with and on the shaft H8. The space between the rotorand stator faces is adjustable within certain limits, by means oi a handlever |23 and can be xed in any adjusted position by means of the member|24. For this purpose the shaft ||8 is in splined connection with thegear H9.

The material to be processed may be fed to the mechanical mixer ||0 at|25. Lines |26, |21 and |28 connect with various critical points withinthe mixer I|0 and with valves |29, |30, I3i, for selectively connectingthese points with the pressure gauge |32 and with the temperature gauge|33 so as to measure and to check the pressure and temperature conditionat these points during the operation of the machine. Drain valves forfacilitating the checking and measuring operation are indicated at |34and |35. These valves may also be employed as sampling valves.

The mechanical mixer is mounted in such a manner that its uppercylindrical outlet portion |36 projects through the bottom of the uppertank l |2 and part way into the tank. At the bottom of the hydrauliccontrol tank l2 is mounted the cylindrical insert or baille 22 formingthe annular suction chamber 36 which is flooded by fluid through theannular space 23. The corresponding parts are designated in Fig. 2 byidentical reference numerals. The suction chamber I6 connects with thesuction line 35, also shown in Fig. 2.

At a central point of the tank ||2 isV mounted the cylindrical insert 24which is provided with ears |40, |4| for attachment to brackets |42, |43secured to the inside wall of the tank ||2. rThe provision of the ears|40 and |4| permits vertical adjustment of the insert or baille 24within the tank.

The cover or lid |45 is centrally provided with the journal member 2lmounting the shaft 26 which carries the' propeller 25. The propeller oragitator may be of a type providing for adjustment of the pitch of theblades. The shaft 2B also carries a suitable gear |48 which intermesheswith gear |49 and the latter is operated by a motor |50 provided with anadjustable speed control |5|. Bevel gears are shown, but any suitabletype of gears, for example, spiral gears or the like, may be used. Themotor |50 with its speed control |5| is secured to a mounting |52 whichis rotatable in a journal |53, and the latter is secured on a bracket|54 carried by the tank |I2. It is thus possible to swing the motor withits speed control and gear |49 out of position away from the tank whenit is desired to remove the tank cover to gain entrance into theinterior. Suitable means are provided for locking the motor assembly inoperating position with the gear |49 meshing with gear |40.

Depending from the tank cover |45 is the circular baffle or insert 28forming the annular suction inlet 29. The annular inlet 28 communicateswith the suction chamber I6 in which is disposed the suction line 34 andthe latter is connected, as shown in Fig. 2, with the valves 50 and 62.

Also depending from the cover |45 is the circular insert or baffle30forming the annular suction inlet 3| which communicates with thesuction chamber 32, the latter communicating with the suction line 33.Line 33, as shown in Fig. 2, connects with the valves 5i and 63.

The sloping walls of the inserts 28 ariell BIJ-may be.- arrangedinhorizontal concentric alignment, as previously discussed.` It should benoted that thediameters of the inlet |36, from themechanical mixer, and;of the annular inlet 29 into the chamber I6', are less than the innerdiameter of the insert 24 and that these elements are `symmetricallyarranged with respect tothe insert 24.

Control devicesfsuch as the float 43, vent valve 42gas outlet 44,pressure gauge 4 I', shown in Fig. 2, and the previously mentionedman-hole or hand-hole are not shown in Fig. 7 but may b e provided.` Inaddition, if desired, provisions may be made for a sight opening eitherin the tank cover or at any convenient point of the tank, and forauxiliary devicesA such as levelgauges and the like.

The operation of the machine shown int Fig. 7 is the same as explainedin connection with Figs. 2 and 3. The material to be processed may beintroduced into the mechanical mixer unit at |25: The mixer unit mayalso be provided with a heating or cooling jacket to be employed asdesired, and the latter may be Supplied with heating or cooling iluid byway of lines IED-46|. The material stream is successively processed in acontrolled manner'within the mechanical mixer and is discharged upwardlyinto thev tank H2. Asy theliquidv rises Within the tank ||2g it floodsiirstthel chamber 3,6 through the annular inlet 23. When theliquidylevel risesV upwardly beyond the propeller 25, the motor |59 may bestarted, to impart `to the liquid a controlled flow so as to circulateiti withinthe tank I |2I along the flow lines indicated in Figs. 2 and3. When the liquid reaches near the top level it floods the chambers I6and 32 through the annular inlets 29 and 3|. The propeller 25'insuchoperation of the machine ha's primarily a flow control.v function.Whatever mixing action will result is incidental. There may, of course,ybe occasion for adjusting the pitch of the blades of the propeller 25and rotating it at such speed asto provide `for agitating turbulencegoing. beyond the ow control proceeding alonggthe oW lines shown inFigs. 2 and 3. Such operation may be carried out, for example, whenthehydraulic control device is initiallyused as a rough mixer tankaspreviously explained. The mixing may also be accomplished mainly Withinthe tank ||2the mechanical'mixer furnishing. the supply and circulationof the material.Y Rough mixing, with the agitator 25y adjusted so as tofurnish agitating rough turbulence, may be followed by ne streamcurrentcontrolled final processing, with the agitator functioning as ailowcontrol element. It shouldbe observed that the suction inletsv 29, 3|,23 are disposed at points, along the. symmetrically designed tankchamber, which will assist the stable hydraulic circulation flow of theliquid in accordance With the ow lines explained before.

The mechanical mixer used in this embodiment is shown on a larger scalein Fig. 8. It comprises the tubular shell carrying the flange i forattachment to the bottom of the tank as shown in Fig. 7. The upper endof the shell |3 6:is shown'cylindrical inFig. 8 but vmay be shaped asindicated in Fig. 7, ormay be pro- Hilr forms the. bottomv of. theshell. |36 and is at,- tached thereto by meai'is` of afbush'ingjl'12.Aft?-` taohell t0 the bottom I'Ll.v iS the-Ili'illtll.1v inylt whichempties into` the. inlet chamber |13. The pipe |2'6 is connected byv asuitable couplingto' the bottom member assho'wrL-so as to` per-`Withdrawal offli'qluidB from the inlet chamber |131, during tpeoperation of the machine, throug'ii the valve |i29`shown-in2Fig". 'Ttotlflepressufrje and temperature gauges' |1327 andI |13?. v'

Statols |15, HB, |11" are mollltevV/'thi the tubular Shell |33 by m'eanS0fthe, tubll1a`inei` oer '|8`. This' member carries brackets: l'I/Qytowhich' is secured the upper bearing |'8 0j. The upper endY of the shaft|8 is'journalled in this bearf ing |80, in spline'd connectiontherewith.' The Shaft iS`Sp1i1ed firsV indicated at |81 for` the I-movable attachment thereto of the rotors |85, |86 andV lfllwhicharesecured' by nuts" [9.0. I it is desired'to use-only one or two ofthese 'rotors insteadof all three, the' rotor: or rotors to befelimffmatedfrom a given" operationv can be remoif'ed and suitable sleeves canbe inserted intheir place; A sleevev I9 I'iskeyedft'o theshaft` |`8"|lat the lower endthereof. This sleeve|9| coacts'with thel'seal |92. Theassemblyis closed at' the bottom. by mean-,sof the p1ate |93; the seal19,2l provicinga. pressureetightf connection. The' shaft" |48'v with itsrotors late-|81, inclusive, is thus' vertically movable Withinthestructure'. A

Attached toy the` shaft H8 at' it's'iower-no adjacent the sleeve'|$||i`isthe krafeeariiigv 26g: "Ihis bearing is secured to anadjusting'member 20| which is provided with a tubular sleevecarr'yng athreadZOZi Arms 263" and 2114 vare secured' at their upper ends tothebushing member |12 and at'their lower ends carry a ring 265,'. Attachedt0 this ringisth'e member 26and`rotatablyse'f cured with respect theretois. the' ring' 208by means of white a nut'zoi can berotatedi tiii nut'being in' threaded engagement with the tiireadzng'carried bythe memberzgl. 'The ringV 208 may be' rotatedb'yl means 'of the lever` |23, andif'itA isL rotated.. it wiii iifttne member 201' by means of' thread2024 upwardly' or downwardly and therefore wiiriiftthe shaft with'itsbearing 200`and`its rotors IBF-|81; inclusive. The'memfbers `2| il' areguide pins forthe upper" plate 21| of the adjusting member ZUI and keepthe' bear-V ing stationary during' rotation of the ring" 208. Anyposition of adjustment can be setand-fisred by means ofthe locking'member'l24`whiohis in threaded engagement With the tubular" sleeve 2|2dependingfrom the' adjustment' member 20|". The ring |24 maybeoperatedbylevers' 213i The inclined surface 2|4"o,ri`the fixed ring 205V"S"`IIJQID vided with calibrations' for ,Coa'fction' with the indexnger'ZlS' which is attached tothe lever |23. The adjustment'provided'for inithis particular machine takes care-ofm'oving the'rot'orswith "rel speci-.Ito the stators from a close positionV of a fewmicronsup tov a maximum distance of`1r"".fv`

The stators carry a` plurality ofV annular axially extending ringsandthe rotors" carry' co'acting annular vrings which interlace lWththestator rings inthe man-ner of turbine blades. The stator as Well as the@rotorringsare tangentially slottedfin amanner toi be described later,soA as to provide alaterallyoutwardly effective'pro pulsion .and.mixingt'force for the liquid to be treat# ed. Such rotorfstatorstructures are broadly known. improvements in details of Ythis particu,lar structure `willnow be described with reference jointly toFigs. 8, 9and yl0.

Fig. l9v isa section through the `firstV .turbine mixer stage formed bystator and rotor |85, taken along lines 9 9 in Fig. 8, looking upwardlyat the rotor |85. The rotor is keyed to the shaft ||8 in splinedconnection therewith, above the sleeve |9|, which is shown in section.The rotor is provided with three annular rings 220, 22|, 222 (see Fig.8), each ring being tangentially slotted in lthe-manner shown in Fig. 9to provide blades or sectors'indicated by the numerals 223, 224, 225,these blades being shown in elevation and vertically shaded. The numberof blades or sectors formed by each annular rotor ring is alike. In thisAcase each ring carries six blades or sectors such as 223, 224, 225, thetangential slots between adjacent blades in blade rings 224 and 225being marked by numerals I-VI.

The stator |15, as shown in Fig. 8, carries two annular rings 226 and221. These annular rings are likewise tangentially slotted as indicatedin Fig. 9, to provide stationary blades or sectors indicated by numerals22B and 229, shown in section and diagonally cross-hatched. These statorrings 226 and 221 are slotted in such a manner as to carry equal numbersof blades such as 228 and 229 (Fig. 9), and in this case there areformed by each statorV ring ve such blades. The tangential slots betweenthe stator blades in each ring form stationary gates marked by I-V.

The direction of rotation of the rotor blades is indicated in Fig. 9 bythe arrows. The 'shell |36, in whichthe mechanism is mounted, isomittedinFig. 9. U

The liquid is introduced for processing through the pipe into the inletchamber |13 shown in Fig. 8. It may be stated at this point that thischamber may be enlarged if-desired, and that separate blades may beattached to the rotor shaft so as to propel the liquid through theupwardly and inwardly sloping space of the chamber |13 in the directionof the interlacing rotor faces of the first turbine mixing stage formedby the stator |15 and the rotor |85. The liquid emerges upwardly(downwardly perpendicularly to the plane of the drawings as viewed inFig. 9) in thel annular space marked in Figs. 8 and 9 by the numeral230. The liquid is scooped up by the six innermost blades 223 of therotor blade ring 22, which act in the manner of an impeller, disposed atthe top of chamber |13, drawing liquid from the chamber, and the liquidis then propelled laterally outwardly into the annular space 23| whichconnects with the inside face of the innermost stator blade ring 221forming the stationary blades 228 and the inner gates I-V indicated inFig. 9. Each turbine stage is thus provided with its own impeller whichcontrols transfer of th'e liquid from the inlet to and through thecorresponding processing level. Escape of the liquid from chamber 23| ispossible only over definite channels. The arrangement provides forescape of liquid successively through the gates I--V of the stationaryblade rings 228.

Assuming, for example, that the mechanism is in the position showninFig. 9, it will be seen that liquid is scooped up by the tips of theinnermost rotor blade rings 223 in the manner indicated by the arrows.Now, following circularly around the space 23| in back of the bladerings 223, in the direction of rotation of the rotor, it will be seenthat the liquid has no chance to escape laterally from the space 23|except through the stationary gate space I between the stationary blades228 which is now aligned with the rotatable gate space I between therotor blades of blade ring 224. The liquid thus enters the secondchamber 231 of the rotor-stator assembly. The next escape of liquid fromchamber 23| into chamber 231 will be upon alignment of the movable gateII between rotor blades 224 with the stationary gate gate space II ofthe stator blades 228.

In short, the liquid escapes from chamber 23| into chamber 231successively by successive alignment, in the direction of rotation ofthe rotor, of the rotor gates I--VI with the stator gates I-V. The vestator gates I-V eject liquid successively in numerical order duringeach revolution of the rotor. v

Following`the chamber 231 annularly aroun in the direction of rotationof the rotor, as shown in Fig. 9, it will be seen that the liquid canescape laterally from this chamber in-the assumed initial position ofthe mechanism only through the gate space I of the outermost statorblades 229, all other spaces being closed by the overlapping relation ofthe stator and rotor blades. This gate space is now in alignment withthe space I of the rotor blades 225 which connects with the channel 240leading to the second turbine stage of the structure formed by thestator |16 and the rotor |86 in Fig. 8. The successive movement of theliquid from the chamber 231 into the space 240 follows the same patternas outlined before in connection with the movement of the liquid fromchamber 23| into chamber 231.

The action resulting from the operation described above maintainscontinuity of the liquid, at the same time subjecting the liquid tocentrifugal and maximum shearing forces which are believed to'bebeneficial for the mixing operation, and cutting down chopping forceswhich would result in a different arrangement of the rotor-statorblades, for example, in an arrangement providing for equal division ofthe tangential slots in the rotor as well as in the stator rings.Another point to be considered in connection with this structure residesin the provision of the chambers 23| and 231 between the rotor bladerings and the adjacent stator blade rings. These chambers equalize thepressure resulting from the operation of the rotor blades and thuscontribute toward maintaining the continuity, and therewith the control,over the fluid stream. The configuration of the rotorstator blades, andthe resulting coaction, provides likewise for continuous and evenpropulsion of the liquid.

The above described operation applies when the rotor faces are in closeattachment with respect to the stator faces. The material will then besubjected to -a combination of centrifugal, shearing, and pressureforces. The mechanism 'will also act to propel the liquid laterallyoutwardly in a steady controlled stream which is constantly subjected tothe shearing and pressure forces. The innermost rotor blade ringsoperate in the nature of a centrifugalpump and adapt the structure foruse as a self-contained unit which after initial priming, as previouslydescribed, performs a pumping action and takes care of the feed of thematerial stream to be processed. With many materials priming will beunnecessary.

The combination of forces as outlined above is desirable in connectionwith the treatment of many materials and is not necessary with othermaterials. The present unit has been designed as an all-purpose machinesuitable' for the treatment of different materials. Therefore, a largelatitude of adjustment in the relation of the rotor-stator faces isprovided, measuring from` a very close adjustment of a few micronsv upto about 1/4, as previously mentioned. As the distance between therotor-stator faces is increased, the shearing and pressure forcesdescribed above are lessened and the outwardly effective centrifugalforces are increased. The impeller action of the rotor blades 224 isincreasingly added to that of the innermost rotor blades 223. Therefore,the amount of material that can be moved through the turbine stage isgreater with increased spacing between the rotor-stator faces, but thepressure and shearing forces may be increased with close adjustment. Amedium adjustment will provide for a churning turbulence due to thecoaction with the stator blades. Very wide adjustment will mainlyfurnish a turbulent continuous flow.

For the reasons outlined above, the mechanism can be used to provide aprocessing treatment similar to that known from ordinary colloid mills,`with such improvements that result from the new structure, and also toprovide mixing agitation for large amounts of material movedtherethrough, and, finally, a turbulent flow for feeding material intothe upper tank.

The pipe 52'! shown in Fig. 8- connects with the valve |38 shown in Fig.7 which in turn is connected with the pressure and temperaturemeasurement instruments |32 and` |33. The pressure and temperatureconditions at this critical point, namely, the first turbine mixingstage, can thus be checked during operation.

Fig, 10, which is a section through the mixer unit shown in Fig. 8 alonglines lll-#I0 thereof, shows the various parts in substantially the samerelationship as explained in connection with Fig. 9, except that theseparts apply to stator |16 and rotor |86. The view is looking down-on thestator |16, the stator blades being shown in elevation, verticallyshaded, and the rotor blades appearing in section and cross-hatched. Theow of liquid to be processed in this mixer stage proceedsperpendicularly upwardly from the plane of the drawing Fig. 10 on thetop of the rotor |85 which is underneath this stage. The liquid isscooped up by the innermost rotor blades, and is subjected to the actionof the laterally outwardly successive rotor-stator blades exactly in thesame way as explained in connection with Fig, 9. The now of the liquiddoes not need to be repeated here in detail,

This mixer stage is provided with a pipe |28 (see Fig. 8) connectingwith the instruments |32 and |33 shown in Fig. '7, so as to permitchecking of temperature and pressure conditions during operation.

Fig. 11 is a sectional view of a modied rotor conforming to the viewshown in Fig. 9. Fig. 12 is a View of a stator coacting with the rotorin Fig. 1l conforming to the view of the stator shown in Fig. l0. Fig.13 is a sectional view showing the essential parts of this modifiedembodiment of rotor and stator and the coaction thereof.

Referring now to these iigures, it will be seen that the rotor isequipped in this case with two blade rings corresponding to theinnermost blade rings in the previous embodiment. The outermost bladering, however, is omitted, and instead there is provided an annularperipheral toothed or suitably serrated portion indicated at 260. I'hestator, Fig. l2, is provided with a peripheral toothed or serratedportion 26| for coaction with the portion 260 of the rotor. The teeth orserrations may be ofany desired' type, in the form of gear teeth,'spiralteeth, or preferably spirall serrations of the general type asusedv inour mills.

The processing by the use of the modified rotor-stator assembly shown inFigs. 11'13 proceeds substantially along the same lines as explainedpasses, and the liquid being propelledA as previ.-

viously explained, by the rotor blades coacting with the stator blades.`The liquid finally arrives at the chamber 26'1 and is then subjectedv toa final processing step between the coacting serrations 260 and 26| ofthe rotors and stators. The liquid moves from the finalV processing stepof this turbinemixer stage upwardly through the channel 288 in thedirection of the arrow.

The mixer unit shown in Fig. 8 may bemou'nte ed for up-flow operation inconnection wththe embodiment Figs. 2 and 3, or for down-now .operationin accordance with the embodiment shown in Figs. 4 and 5.

The machine` disclosed herein will bey found usefulfor many purposesincluding, for example, homogenizing of milk, the processing of numerousfood products, preparation of. bituminous emulsions, chemical andpharmaceutical preparations, and also in the mixing of colloidal fuelconsisting of coal particles dispersed in fuel oil. Certain features ofthe invention may be found useful in apparatus other than mixers of thetypes specifically mentioned herein, Modications may be made with regardto structure as Welll as to function. Attention may be called, e. g.,tothe fact that one or the other of the chambers through which liquid iswithdrawn may be employed, if desired, for adding substances forintermixing with the circulating fluid body. The machine made inaccordance with the invention is a versatile unit and itsfusefulnesswill increase with the ingenuity of the operator.

The invention may be used, and changes may be made, within the scope andspirit of the following claims which dene what is considered new anddesired to have protected4 by Letters Patent of the United States.

It is understood, however, thatthe scope of claims which define acombination, iirst, of means for subjecting material to irrationalturbulence and, second, of means for then subjecting the material tohydraulic displacement or agitation without creating irrationalturbulence therein, or equivalent language, is limited to arrangementswherein said first and said second means form a machine unit whichpermits transfer of the irrationally intermixed turbulent material fromsaid first means directly and immediately to said second means withoutincurring segregation or agglomeration of the material componentsincident to such transfer of the material. Arrangements comprisingseparate mixers or the like, which are separately disposed and areinterconnected by pipes or the like wherein segregation or agglomerationof material would occur incident to transfer of material therethroughare, accordingly, disclaimed from the scope of such claims.

I claim:

. disposed within the 1. Apparatus for mixing and blending fluidmaterials having a tank for receiving material and for subjecting thematerial therein to va circulatory mixing displacement which includesmaterial flow generally centrally axially of the tank followed bylateral outward deflection near one end of the tank to circulate thematerial generally peripherally Vin reverse direction toward theopposite end of the tank where the material is laterally inwardlydeflected for intermixture with the generally axially directed flow, theimprovement which consists in the provisiongof tubular baille meansdisposed within the tank centrally at one end thereof to guide thelateral outward deflection of the material, baffle means tankperipherally at the identical end thereof for guiding the laterallyoutwardly deflected material to flow peripherally toward the oppositeend of the tank, and baille means disposed within the tank at theopposite end thereof for guiding the lateral inward deflection of thematerial, said baille means being so constructed and arranged that thematerial is displaced in its circulatory motion substantially withoutcreating irrational turbulence therein.

2. The structure defined in claim 1, together with means for applyingsuction to the circulating material body peripherally thereof for thepurpose of sustaining its circulatory motion.

3. The structure dened in claim 1, wherein each of said baille meansforms a chamber for confining an amount of material, and means in eachof said chambers for withdrawing material therefrom to create suctionareas peripherally of the circulating fluid body for the purpose ofsustaining the circulation thereof.

4. The structure defined in claim 1, wherein .said baille means formschambers for confining .amounts of material peripherally of saidcirculating material body, means for selectively ,withdrawing materialfrom said chambers to create suction peripherally of the circulatingfluid body for the purpose of sustaining the circulatory displacementthereof, and means for intermixing withdrawn amounts of material withthe main flow of material in said tank.

5. In a machine having a tank for receiving a fluid medium and materialfor dispersion therein by intermixture therewith and having means forinjecting such fluid medium into said tank for upflow therein, theimprovement which consists in the provision of flow-controlling meanscomprising a tubular downwardly and inwardly directed member disposedwithin said tank centrally axially at the top thereof and extending intothe upper strata of the fluid medium therein, and a tubular downwardlyand outwardly directed member disposed Within said tank peripherallyannularly at the top thereof in concentric relation with respect to saidfirst-named member and substantially at the same horizontal leveltherewith, said members forming in the upper strata of said fluid mediuman annular symmetrically constricted areafrofupwardly symmetricallydecreasing dimension for the purpose of symmetrically and uniformlydeilecting the upflow of said fluid medium to obtain hydraulicdisplacement thereof without creating irrational turbulence therein.

6. Apparatus for handling duid materials comprising an upright tank,means forming an inlet disposed centrally axially of said tank at oneend thereof for injecting a stream of fluid material thereinto to form afluid body therein, a plurality of baffle means disposed in said tankadjacent the wall thereof and forming a plurality of separate confinedchambers each of which communicates hydraulically with said fluid bodysolely peripherally thereof, and means for selectively withdrawing iluidmaterial from said chambers and for selectively directing such withdrawnmaterial to discharge and/or for re-injection through said inlet.

7. The structure and combination defined in claim 6, together with meansin said inlet for regulating the flow of material therethrough.

8. The structure and combination defined in claim 6, together with meansforming a tubular extension which projects from said inlet into the tankcentrally axially thereof for guiding .the flow of the stream of fluidmaterial thereinto.

GEORGE A. AUER.

